State tax filing

Please clarify....

" Do I have to file a PA Return to get a refund and then file a NJ Return to pay them?

You do!  Be sure to take credit on your resident return  for the taxes paid to the nonresident state."

I will file a PA State Tax return and expect a full refund of the PA State Taxes paid.  I don't understand the statement "Be sure to take credit on your resident return...".  Don't I need to pay the full amount to NJ (including the State Taxes I paid to PA)??  Why am I taking a credit if I'm expecting reimbursement from PA?  It would be ideal if I didn't have to wait for the PA refund to pay NJ and TT would handle the refund / credit!